This paper investigates claims of high guardrail damage rates for guardrail end terminals in high snowfall areas and recommends a selection of terminals for use in high snowfall areas based on an evaluation of end terminal specifications and a survey of eight northern tier state Departments of Transportation (DOT) that use these terminals. In areas of significant snowfall levels and cold temperatures, agencies need an end terminal that can withstand these conditions, resist damage during snow removal activities, and be readily repaired without having to excavate or drive posts into frozen ground. Furthermore, any viable end terminal must meet the National Cooperative Highway Research Program (NCHRP) Report 350 standards. This paper recommends eliminating all terminals that do not use sleeved steel posts. Wooden posts tend to shear-away at the top of the soil tube whereas steel posts can be replaced year-round. Part of minimizing the danger to the end terminals during snow removal activities relies on more effective marking strategies and improved awareness and caution among winter maintenance crews. While this study ranks all of the alternative end terminals, those without steel posts and a limited percentage of posts sleeved cannot be recommended. Two terminal types, the sequential kinking terminal (SKT) and the ET-2000, emerge from the evaluation as the preferred designs for high snowfall regions because they use steel posts and sleeve all of their posts. While many of the other alternatives may prove adequate for many sites, only the ET-2000 and SKT are recommended for use in high snowfall regions at this time. More research is required to identify a single terminal as the best alternative because the user data exhibits limited variability.
展开▼
